Ingot mold



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I INVENTOR W//mm /Yfzga may@ 13%17 ATTORNEY JHM! Rg, HQE@ W, M RAMAGE ZL INGOT MOLD Filed Jan. 28, 1926 3 Sheets-Sheet 3 INVENTOR ATTORNEY I i 5 The ingot mol .lilly i6, 1929..

UNITED STATES PATENT OFFICE.

WILLIAM IHAIG RAMAGE, OIF GIRARD, OHIO, ASSIGNOR T VALLEY MOULD #c IRON CORPORATION, OF SHARPSVILLE, PENNSYLVANIA, A CORPORATION 0F NEW YORK.

INGOT MOLD.

Application led January 28, 1926. Serial No. 84,307.

rlhe present invention relates broadly to metallurgy and more especially to an ingot mold for steel ingots and the like, and the method of makin the same.

art for the manufacture of ingot molds has grown up largely on merely the basis of providing` a container Which Would comprise a .mold for casting steel ingots of the desired'size and shape. Considerable attention has been directed to prolonging the life of molds and to various incidental characteristics Without much consideration of the eect on the ingot produced by the arrangement of the Weight or character of metal l5 in the side Walls of the mold. rThis has particularly been' true in connection with the vertical type of ingot molds.

It has been observed that when hot ingots are stripped from the ordinary ingot mold,

` that certain portions of the "ingot are much darker in appearance than other portions; for example, it is not uncommon that when an ingot is stripped from the mold the corners of the ingot and usually both ends will be cooled sufficiently to appear black While the side Walls and the middle portion of the ingot will be red hot. In View ofthe fact that uneven cooling of the ingot, particularly in its formative stage, produces uneven characteristics in the ingot itself, this results in an ingot in Which the metal is not of uniform characteristics and the interior of the ingot is under varying internal stresses. When such an ingot is fabricated, these varying characteristics produce non-uniform steel conditions in the fabricated article. Furthermore, as incidental to these objections, surface cavities and cracks are liable to occur in the manipulations of the prior art ingot during the various steps leading to the finishing operation. Where such defects occur, a condition usually arises which is liable to result in a hidden defect in the iinished article due to the fact that the cracks or cavities of any vkind when once exposed are rendered incapable of being properly Welded during the subsequent fabricating` operation.

The present invention overcomes the difmethod for producing the novel ingot mold, and the novel ingot hereinafter more fully disclosed.

The method by which the novel ingot mold of the present invention isdesigned and constructed comprises producing an ingot mold culties of the known art by .providing al of cast iron or the like with side Walls of the usual form heretofore known in the art and then byforming openings in said side walls, by drilllng or otherwise, of different depths into which thermometric devices may be inserted over various parts of the mold and in different depths in the side Wall thereof. By this means, the thermometric condition of the side Walls of the mold may be observed when the mold is filled with molten steel. lin view of the fact that the rate of cooling of the steel ingot may be regulated by the thickness of the ingot mold Walls, those parts of the mold Wall which show a higher temperature indicate that the mass of cast iron, or the like, in the side Wall of the mold should be increased at these points and should be decreased adjacent the points Where the temperature isloWer. By means of the information obtained through the use of this method, temperature curves may be established which indicate the relative thickness of the mold Wall adjacent a definite section or zone of the ingot. Une convenient method of ascertaining this information is to utilize electro-thermometric devices which aHord quick readings for a larger number of test points over the test mold Wall.

The novel ingot mold of the present invention is one in which the heat absorbing capability ofthe side Walls is differentially proportioned in such manner that When an lngot is poured therein, the side surfaces of ingots are of a substantially uniform temperature during the time the ingot is in the mold. This may be done in several Ways.

rllhe novel ingot mold built upon the temperature curves may be varied in shape, depending upon the shape of the matrln which determines the shape of the ingot Whlch 1s to be produced.y Where the ingot comprlses a longitudinal mass having a substantiallyI square cross section, the preferred forni of the mold assumes a shape which in vertical cross section has side Walls somewhat barrel shaped in their outer configuration. In big-enddown molds, the largest diameter is somewhat below the vertical lnid portion of the mold and in horizontal cross section the mold assumes that of a distorted circle` with the thinnest metal adjacent the corners of the matrix and the metal being thicker opposite the side faces of thehiihatrix. The metal preferably, though not necessarily, is distributed both horizontally and vertically in such manioo ner that when the steel for the ingot is poured, and the mold completely filled the rate of absorption by the mold walls of heat from the steel shall be such that the temperature on the side walls of the ingot shall be substantially uniform over the entire side wall surfaces. l Where an ingot cast in this type of mold is stripped while at a red heat, the entire surfaces of the ingot, including the cor` ners, will be of substantially uniform color. This results in aningot of steel or the like having a uniform chill over its rolling surfaces so that the skin of the ingot is uniform throughout and the internal metal ofthe ingot is in a neutral stress condition.` This obviates the difficulties encountered in the production of ingots by use of previously known ingot molds ofthe old art and avoids the defects of cracks, etc., heretofore encountered.

It is to be understood that under certain conditions, the distribution of the metal in the side walls of the mold may be satisfactorily arranged in accordance with one feature of the present invention without considering the distribution'from a vertical standpoint, that is, that the metal may be distributed in hori vzoiital zones of the mold side wall in such manner as to produce the desired' effect and avoid some of the -major difficulties. Ingots cast insuch molds may be commercially satisfactory, but will not be as good as those cast in the preferred form of mold where both horizontal and vertical distribution of metal in the 'mold side walls is properly done. The molds those herein in which horizontal differential distribution of metal alone is provided, is part ofthe resent invention, but is only one feature,` o the preferred form.

Realizing that the presentY method, the mold, and the ingot, may be carried out or produced by steps or shapes different from specifically specified, it is to be understood that the disclosure herewith in the specication and drawings is to be considered as illustrative and not in the limitinsense. Y

d ig. lis a diagrammatic illustration showing a cross section through one form of ingot mold Yin accordance with the present invention. l

Fig. 2 is a plan view looking at the bottom of the ingot mold shown in Fig. 1.

Fig. 3 is a plan View of the bottom of an ingot mold having the matrix side walls convex.

Fig. 4 illustrates another form of ingot mold in which the matrix of the mold comprises side walls having zones of different degrees of taper. .l ig. 5 is a further diagrammatic view illustrating a vertical cross section through a mold and in which the sidewalls of the matrix are illustrated as being curved.

Fig. 6 is a diagrammatic view of the thermometric devices which may be utilized in connection with the method of making the thermally balanced ingot molds comprising thepresent invention. d Referring now more specially to Figs. l and 2, the matrix portion 1 of the mold is illustrated as being that of a substantially square horizontal cross section and with the big-end-down, it being understood,l however, that the invention is equally applicable to the casting of ingots with the big-end-up. The mold is adapted to set upon a stool 2, which preferably is provided with uide ears 4 to center the mold on the stool. his stool may be arranged with a recess 5 preferably having its middle portion coincident with the longitudinal axis of the mold. In the preferred form of mold as illustrated in Fig. 1, the outer side walls of the mold as illustrated in vertical cross section are inclined outwardly and'upwardly to increase the metal in the side walls adjacent the zone 6 which is slightly below the vertical middle portion of the matrix. From the zone 6, the side walls taper upwardly toward the mouth of the ingot mold 1n such manner that the weight of the metal in the side, walls of the ingot mold shall be so proportioned as to absorb the heat from the molten steel at such a rate that after the ingot is poured the side walls of the ingot shall be of substantially uniform temperature from top to bottom. l

Referring to Fig. 2, it will be -observed that the metal in the side Walls is thinnest adjacent the corners 7 and thickest adjacent the `liat sides of the matrix as at 8. j

Referring to Fig. 3, it will be observed that the thickness of the metal, the vertical opposite side wall's of the matrix, is partiall obtained by curving the side walls vertical y inward in horizontal cross section as at 9; so that the desired weight of metal in the side walls of the mold is obtained with less curvature to the outside of the mold.

In Fig. 4, the weight of the metal in the side walls of the mold in its vertical cross section is obtained by shaping the matrix of the mold in such manner that the lower portion of the mold 10 has a greater taper than the upper portiony 11.

Referring now to Fig. 5, the side walls of the mold are shown with the desired weight of metal, in the vertical cross-section, bein obtained by use of a curved side wall matrix in which the side walls gradually narrow from one end of the mold to the other so that the ingot may be stripped from the mold when the ingot is cast.

In all of the designs herein illustrated, it is `to be understood that the greatest mass of metal in the side Walls of the mold 'is arranged opposite that part of the ingot which under normal` conditions (when cast perature *when the ingot is strippe suitable Referring now to Fig. 6, (which illustrates diagrammatically one form of apparatus which may be used in designing molds comprising the present invention), an ingot mold 12v of the ordinary tapered side wall type is drilled at Various points, such as 14, 15, and 16, with the drill holes extending various depths into the mold side wall so that one drill hole will be near the inner or matrix face of the mold, the next may be adjacent the middle of the mold side wall and the third opening of lesser depth or near the outer surface of the mold. These openings are provided With suitable thermo-couples which are connected by circuits 17 with a selective switch 18 that leads to a suitable measuring device adapted to respond in accordance with the temperatures at the point where the thermo-couple is placed. Fig. 6 illustrates only a very few of the many thermo-couples which will be used in practice; so that by the means suggested the temperature conditions in any part of the mold may be quickly obtained. Once having obtained the temperature curves of the mold when it is filled with. molten steel t0 cast an ingot. the thermometricallybalanced ingot mold comprising the present invention is then designed with the weight of the metal in the lside Walls in accordance with the foregoing explanation.i

Where the term uniform temperature is used in the claims, this term is not to be confused with Y constant temperature. As

" soon as the steel is poured and the ingot begins to freeze, the' temperature thereof will begin to fall and will continue to fall until the ingot is cooled. rThe term uniform temperature therefore as used in the claims means that at a given moment of time, the temperature conditions at one point shall be substantially the same as at another point.

The present invention is particularly important in the manufacture of steel ingots, but is applicable to molds for any metal cast in ingots for subsequent working such as rolling or forging.

Having described my invention, what l claim is 1. As an article of manufacture, a vertical metallic ingot mold for use in casting metallic ingots and having a matrix cross section providedwith corners, the metal in the side walls of said mold being thicker in the middle of the side Walls than at the corners, said metal being so distributed that the rate of cooling of an ingot cast in said mold shall be substantially equal on the side Walls and at the corners in suchvmanner that the side walls and corners are maintained at substantially' l the same temperature While an ingot is cooling in the mold.

2. An article of manufacture, a metal ingot mold having the metal in the side walls thicker adjacent the mid-portion of the side walls than adjacent the corners thereof. and with the metal in said side walls being distributed as to thickness and heat absorbing capacity to maintain an even temperature over substantially the entire matrix surfaces during freezing of an ingot in said mold.

3. An article of manufacture comprising a cast iron ingot mold for casting steel ingots, said mold having the thickness of the side Walls greatest adjacent the mid-portion thereof and being proportioned to balance heat given olf by molten steel filling the matrix of said mold to provide a substantially even temperature over the surfaces of the matrix walls during the freezing of a steel ingot in said mold. v

4. A cast iron lnold for casting steel ingots comprising means adjacent the mid-portion of the walls having heat absorbing capacities balanced relative to the heat thrown olf by the molten steel filling the matrix of the mold to maintain the surfaces of a steel ingot within said mold at substantially uniform temperature during the freezing of the ingot.

5. An article of manufacture comprising a cast iron ingot lnold for casting steel ingots, means adjacent the mid-portion of the walls having heat disposing capacity balanced relative to the heat thrown out. by molten steel during casting an ingot in the mold to provide a substantially uniform temperature over the surface of the ingot when the ingot is frozen and ready t0 be stripped from the mold.

6. A vertical cast iron ingot mold adapted for casting steel ingots, the metal in the side walls of the mold gradually increasing in thickness from the corners to the mid-portion of the side walls and being thickest adjacent that portion of the matrix from which the maximum amount of heat is dissipated during the freezing of molten steel to form an ingot within said mold.

7. A vertical cast iron ingot mold adapted to cast steel ingots, the metal in the side Walls of said mold being thicker at the middle of the side Walls than at the corners and being proportioned in thickness to the heat capacity of molten steel forming an ingot in the matrlx of said mold whereby when a frozen ingot is stripped from said mold the surfaces of said ingot are of substantially uniform heat.

8. A Vertical ingot mold for casting steel ingots, the side walls of said mold having the thickness thereof greatest adjacent the 1mdportion of the side Walls and with the thickness of said walls being proportional to the amount of heat given off by the freezing of an ingot from molten metal in the matrix of said mold whereby a frozen ingot stripped from said mold is of substantial uniform circum- V ferential temperature.

So i

mined relatively to the horizontal cross section of the matrix'of the mold with the thickest metal comprising the mid-portion of the side walls and being adjacent the hottest zone of the matrix when a metallic ingot is being frozen in said mold and whereby the circumferential temperatures of the surfaces of an ingot cast in said mold are maintained at substantially uniform temperatures when the in` got is cooling in the mold.

10. Avertical ingot mold for casting steel ingots, the thickness of the metal in the side walls of the mold being predetermined to the matrix and the length `of the mold with the thickest metal being slightly below the vertical middle portion of the matrix and being adjacent the hottest zone of the matrix when a. metallic ingot is being frozen in said mold,

form throughout the length of the mold While the ingot is cooling in the mold.

11. A'vertical ingot mold for casting steel ingots having a poly-sided cross section provided With corners, the thickness of the metal in the side Walls being greater than at the corners, said thickness being predetermined relatively to the shape of the matrix with the hottest metal adjacent the thickest zone of the matrix when a steel ingot is being frozen from melted steel in said mold whereby the side Walls and'corners of the matrix are maintained at substantially uniform temperature While an ingot is cooling in the mold.

WILLIAM HMG RAMAGE. 

